SSH(1) SSH(1)
NAME
ssh - secure shell remote login client
SYNOPSIS
ssh [ -drRX ] [ -t thumbfile ] [ -T tries ] [ -u user ] [ -h
] [ user@]host [ -W remote!port ] [ cmd args ... ]
DESCRIPTION
Ssh starts a remote shell or cmd on the computer host logged
in as user. The input file descriptor is forwarded to the
remote side and output and error descriptors are forwarded
to the local side.
The connection is authenticated and encrypted using the SSH2
protocol. The user authenticates itself to the host using
his RSA key pair (stored in factotum) or plaintext pass-
words. To authenticate the host to the user, the hosts RSA
public key is hashed and compared to the entries in
$home/lib/sshthumbs file (see thumbprint(6)). The thumbfile
location can be changed with the -t option.
When cmd is specified, it is concatenated with the list of
quoted args and run on the remote side. No pseudo terminal
will be requested. A cmd beginning with # is interpreted as
a subsystem name such as sftp (see sshfs(4)).
Without cmd, a shell is started on the remote side. In that
case and when the $TERM environment variable is set (such as
when started under a terminal emulator like vt(1)), a pseudo
terminal will be requested for the shell. This can be dis-
abled with the -R flag. A pseudo-terminal can be requested
in all cases with the -r flag.
With the -W option, instead of executing a command remotely,
makes the server dial a tcp connection to remote!port which
the client relays on standard input and output. For han-
dling multiple connections transparently to programs, see
sshnet(4).
The -d flag enables debug output.
The -X flag enables mux mode, which after establishing the
tunnel, relays the plaintext SSH protocol messages on file-
descriptor 0 and 1. This is used by programs such as
sshnet(4) and sshfs(4).
FILES
$home/lib/sshthumbs the user's thumbfile of known host fin-
gerprints
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SSH(1) SSH(1)
SOURCE
/sys/src/cmd/ssh.c
BUGS
If keyboard-interactive authentication fails, by default it
is retried three times. The number of tries can be changed
with -T. Setting it to zero disables keyboard-interactive
authentication.
SEE ALSO
vt(1), rsa(8), thumbprint(6), factotum(4), sshfs(4),
sshnet(4)
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